As fastener chains, a fastener chain is known, which includes a pair of rectangular tapes having a length direction and a width direction and a pair of element rows fixed on core portions extending along opposing side edge portions of the pair of tapes, in which each element rows is constituted of a plurality of elements.
As conventional examples of elements, an element is known, which includes a body portion fixed on the core portion of the tape, a neck portion protruding from the body portion toward the opposing tape, a pair of shoulder portions protruding from the neck portion toward both sides in the length direction, an engaging head portion protruding from the neck portion toward the opposing tape, and a pair of groove portions formed in both sides, in the length direction, of the engaging head portion and communicated with each other in the length direction (see Patent Document 1).
As viewed in the width direction, the pair of groove portions and the pair of shoulder portions are formed to be parallel to an extending direction of the core portion on which the element itself is fixed. Accordingly, in a case where a fastener chain is made using a plurality of such elements, if no external force is exerted on the closed fastener chain, the core portion extends in a straight line shape, and the fastener chain extends in a straight line shape to be parallel to an extending direction of the core portion as viewed in the width direction.